Our weekly trip through San Diego history features the opening of the Otay Mesa border crossing, the space shuttle Challenger explosion and two Super Bowls. Plus your latest chance to win a book in our trivia contest and a new "where were you?" feature. Read on.

Jan. 22: In 2003 the Padres announced a $60 million, 22-year deal with a San Diego-based pet supply company to name the team's new ballpark Petco Park. Shenanigans ensued.

Jan. 23: In 2004 the world's first genetically cloned banteng went on display at the San Diego Zoo. A zoo spokesman called it the public's first opportunity anywhere to see a cloned animal from an endangered species. Scientists saw an opportunity. To clone more animals no one's ever heard of.

Jan. 24: In 1985 the 25th border crossing between the United States and Mexico officially opened at Otay Mesa following 17 years of planning. Fewer than 20 cars passed between the countries that first day. By 2003, when the crossing began around-the-clock operations, more than 11 million people were crossing annually. Last year, 9.8 million people crossed, according to U.S. Customs and Border Protection.

Jan. 25: In 1998 the Denver Broncos beat the Green Bay Packers in Super Bowl XXXII at Qualcomm Stadium, forming the first half of a one-two punch that would make history in the fall when the venue hosted the World Series as well and became the first facility in the country to host both sporting events in the same year.

Jan. 26: In 2003 the Tampa Bay Buccaneers beat the Oakland Raiders in Super Bowl XXXVII at Qualcomm Stadium, the third Super Bowl at the venue in 15 years and, most likely, according to the National Football League's commissioner, the last one it would ever get. At this point, fans would settle for a single playoff game in the 44-year-old facility....

Jan. 27: In 1982 about a quarter of the Crystal Pier tumbled into the water when unusually rough surf dislodged nearly 250 feet of the 1,000 foot long landmark. It was one of 10 Southern California piers to suffer damage from the winter storms that year.

Jan. 28: In 1986 the space shuttle Challenger exploded after liftoff, killing Concord, N.H., school teacher Christa McAuliffe and six other astronauts. La Jolla teacher Gloria McMillan, who was the California finalist to become the first teacher in space but missed the cut to become one of 10 semifinalists for the distinction, watched the tragedy from the ground at Cape Canaveral, Florida.

Where were you when the Challenger exploded? Share your memories in the comments section below. If I get some interesting stories, I'll write a separate post on them.

Our weekly giveaway

Email your answers to our trivia question by 5 p.m. Tuesday to have a shot at winning a nonfiction book from the U-T library. One winner will be chosen in a random drawing of all the correct answers emailed to matthew.hall@uniontrib.com.

A helpful hint: You don't have to scour the Internet for the answer. You'll find it via a link on this page.